Current Drug Delivery - Volume 20, Issue 10, 2023

The disadvantages of active ingredients extracted from medicinal plants due to poor solubility in the body and low bioavailability limit their clinical application. Pharmaceutical cocrystal as a new type of drug in solid form has attracted the attention of researchers. This article reviews the effects of cocrystal in various poorly soluble herbal active ingredients of medicinal plants on their physicochemical properties and biological properties and provides references for the application of pharmaceutical cocrystal in poorly soluble active compounds of medicinal plants.

Estimating parameters such as pulmonary drug disposition and deposited dose, as well as determining the influence of pulmonary pharmacokinetics (PK) on drug efficacy and safety, are critical factors for the development of inhaled drug products and help to achieve a better understanding of the drugs’ fate in the lungs. Pulmonary disposition and PK have remained poorly understood due to the difficulty to access pulmonary fluids, compared to other biological fluids, such as plasma, for direct or surrogate measurement of the concentration of the active compounds and their metabolites in the lung. The use of the isolated perfused lung model (IPL) has become more common, and it is considered a useful tool to increase understanding in this area since it offers the possibility of controlling the administration and easier sampling of perfusate and lavage fluid. The model also provides an opportunity to study the relationship between PK and pharmacodynamics. This review describes the fundamentals of the IPL model, such as preparation and setting up the method, species selection, drug administration, and lung viability investigation. Besides, different applications of the IPL model like pharmacodynamic studies, pharmacokinetic parameters studies such as absorption, distribution, and metabolism, and evaluation of inhaled formulation have also been reviewed.

COVID-19 pandemic is the biggest global crisis. The frequent mutations in coronavirus to generate new mutants are of major concern. The pathophysiology of SARS-CoV-2 infection has been well studied to find suitable molecular targets and candidate drugs for effective treatment. FDArecommended etiotropic therapies are currently followed along with mass vaccination. The drug delivery system and the route of administration have a great role in enhancing the efficacy of therapeutic agents and vaccines. Since COVID-19 primarily infects the lungs in the affected individuals, pulmonary administration may be the best possible route for the treatment of COVID-19. Liposomes, solid lipid nanoparticles, polymeric nanoparticles, porous microsphere, dendrimers, and nanoparticles encapsulated microparticles are the most suitable drug delivery systems for targeted drug delivery. The solubility, permeability, chemical stability, and biodegradability of drug molecules are the key factors for the right selection of suitable nanocarriers. The application of nanotechnology has been instrumental in the successful development of mRNA, DNA and subunit vaccines, as well as the delivery of COVID-19 therapeutic agents.

Background: Many dyes or radioactive markers used for sentinel lymph node (SLN) have the shortcomings of false positive and radiation injury. Indocyanine green (ICG) seems to have a lower false positive rate and tissue damage, without a clear field of vision during the operation. Methods: For the shortcomings, we successfully synthesized three anionic pullulan materials, changed the degree of hydrophobic for size controlling (< 50nm) to prepare CHP nanoparticles (NPs) and changed the succinyl degree to prepare CHPC NPs with different negative surface potential. Results: The size of those NPs were less than 50nm under (transmission electron microscope) TEM, with hydrodynamic size of 90.67 ± 2.2 nm of CHP, 105.8 ± 1.7 nm of CHPC1 and 115.9 ± 2.3 nm of CHPC2. Moreover, the Zeta potential of CHP, CHPC1 and CHPC2 were -1.9 ± 0.2 mV, -9.6 ± 0.3 mV and -19.4 ± 0.7 mV. The size of ICG-loading CHP, CHPC1 and CHPC2 NPs increased to 109.4 ± 2.7 nm, 113.8 ± 1.2 nm and 30.6 ± 3.5 nm, as the zeta potential decreased to -2.7 ± 0.4 mV, -12.5 ± 1.6 mV and -23.1 ± 1.2 mV. With the increasing degree of succinyl, the size increased and the zeta potential decreased. At the same time, the higher degree of succinyl drug-loading NPs have lower release and have increased the stability of ICG. We found that the blank-NPs had no significant toxicity to normal cells (HSF), as the ICG@CHP group had larger toxicity than the CHPCs and control. Moreover, the cellular uptake was decreased with the increased degree of succinyl. Conclusion: In this study, we successfully prepared CHPC2 carriers with the maximum negative surface charge, for follow-up research and providing new ideas for SLN.

Background: The antiretroviral protease inhibitor drug, lopinavir (LPV), is used to treat HIV-1 infection. LPV is known to have limited oral bioavailability, which may be attributed to its poor aqueous solubility, low efficacy and high first-pass metabolism. Self-nanoemulsifying drug delivery systems (SNEDDS) for LPV have been developed and optimised to counter the current issues. Methods: The titration method was used to prepare LPV-loaded SNEDDS (LPV-SNEDDS). Six different pseudo-ternary phase diagrams were constructed to identify the nanoemulsifying region. The developed formulations were chosen in terms of globule size < 100 nm, dispersity ≤ 0.5, dispersibility (Grade A) and% transmittance > 85. Heating-cooling cycle, freeze-thaw cycle, and centrifugation studies were performed to confirm the stability of the developed SNEDDS. Results: The final LPV-SNEDDS (L-14) droplet size was 58.18 ± 0.62 nm, with polydispersity index, zeta potential, and entrapment efficiency (EE%) values of 0.326 ± 0.005, -22.08 ± 1.2 mV, and 98.93 ± 1.18%, respectively. According to high-resolution transmission electron microscopy (HRTEM) analysis, the droplets in the optimised formulation were < 60 nm in size. The selected SNEDDS released nearly 99% of the LPV within 30 min, which was significantly (p < 0.05) higher than the LPV-suspension in methylcellulose (0.5% w/v). It indicates the potential use of SNEDDS to enhance the solubility of LPV, which eventually could help improve the oral bioavailability of LPV. The Caco-2 cellular uptake study showed a significantly (p < 0.05) higher LPV uptake from the SNEEDS (LPV-SNEDDS-L-14) than the free LPV (LPV-suspension). Conclusion: The LPV-SNEDDS could be a potential carrier for LPV oral delivery.

Background: Currently, the treatment protocols for tuberculosis (TB) have several challenges, such as inconsistent oral bioavailability, dose-related adverse effects, and off-target drug toxicity. Methods: This research reports the design and characterization of rifampicin (RIF) and isoniazid (INH) loaded hybrid lipid-polysaccharide nanoparticles using the solvent injection method, and demonstrated the influence of conjugated mannosyl residue on macrophage targeting and intracellular drug delivery capacity. Results: The nanospheres, herein called mannose-decorated lipopolysaccharide nanoparticles, were spherical in shape, exhibiting average sizes less than 120 nm (PDI<0.20) and positive zeta potentials. Drug encapsulation was greater than 50% for rifampicin and 60% for isoniazid. The pH-responsive drug release was sustained over a 48-hour period and preferentially released more rifampicin/isoniazid in a simulated acidic phagolysosomal environment (pH 4.8) than in a simulated physiological medium. TGA and FTIR analysis confirmed successful mannose-grafting on nanoparticle surface and optimal degree of mannosylation was achieved within 48-hour mannose-lipopolysaccharide reaction time. The mannosylated nanoparticles were biocompatible and demonstrated a significant improvement towards uptake by RAW 264.7 cells, producing higher intracellular RIF/INH accumulation when compared to the unmannosylated nanocarriers. Conclusion: Overall, the experimental results suggested that mannose-decorated lipopolysaccharide nanosystems hold promise towards safe and efficacious macrophage-targeted delivery of anti-TB therapeutics.

Background: L-Ascorbic acid (AA) is a highly unstable compound, thus, limiting its use in pharmaceutical and cosmetic products, particularly at higher concentrations. Objective: This study aimed to stabilize the highly sensitive molecule (AA) by encapsulating it in β- cyclodextrin nanosponges (β-CD NS) that can be used further in preparing cosmeceuticals products with higher AA concentrations and enhanced stability. Methods: The NS has been synthesized by the melting method. The AA was encapsulated in β-CD NS by the freeze-drying process. The prepared NS were characterized by FTIR spectrometry, SEM, Atomic Force Microscopy (AFM), zeta sizer, Differential Scanning Calorimetry (DSC), and the physical flow characteristics were also studied. The in vitro drug release was carried out on the Franz apparatus using a combination of two methods: sample & separate and dialysis membrane. The assay was performed using a validated spectrometric method. Results: The entrapment efficiency of AA in β-CD NS indicated a good loading capacity (83.57±6.35%). The FTIR, SEM, AFM, and DSC results confirmed the encapsulation of AA in β-CD NS. The particle size, polydispersity index, and zeta potential results ascertained the formation of stabilized monodisperse nanoparticles. The physical flow characteristics showed good flow properties. Around 84% AA has been released from the NS in 4 h following the Korsmeyer-Peppas model. The AA-loaded NS remained stable for nine months when stored at 30±2°C/65±5% RH. Conclusion: It is concluded that the prepared NS can protect the highly sensitive AA from degradation and provide an extended-release of the vitamin. The prepared AA-loaded β-CD NS can be used to formulate other cosmeceutical dosage forms with better stability and effect.

Background: When administered transdermally, desonide is ineffective due to its poor solubility. As a new transdermal delivery system, nanoemulsion gel has demonstrated significant advantages for drug delivery over conventional formulations. We have established desonide nanoemulsion gel (DES NE gel) for better transdermal absorption, but its efficacy and safety still need to be evaluated. This study aims to provide additional evidence demonstrating the improved pharmacodynamics and safety of transdermal delivery of Desonide via nanoemulsion gel. Methods: Pharmacodynamics and safety of Desonide nanoemulsion gel were evaluated using Desonate ^® as the reference formulation. To assess the difference in curative effect between DES NE gel and Desonate^® and to ensure safety, atopic dermatitis (AD) models in KM mice were developed using 2,4-dinitrofluorobenzene (DNFB). The degree of ear swelling, ear mass difference, thymus, spleen index, and HE conventional pathology of mice were used as pharmacodynamic evaluation indexes, and the irritation was predicted by the New Zealand rabbit epidermal stimulation assay. Results: Nanoemulsion gels may facilitate transdermal penetration of drugs by influencing the skin condition. Medium and high doses of DES NE gel significantly ameliorated the inflammation and swelling of the ear caused by dermatitis/eczema in mice. In addition, compared with DES gel, skin irritation extent did not increase. Conclusion: Nanoemulsion gel can be applied to improve the efficacy of drugs with low potency or poor solubility. DES NE gel provides a higher transdermal potential than other delivery systems. In this study, it was found that nanoemulsion gel is a promising percutaneous carrier of DES. DES NE-GEL has a significant curative effect on dermatitis/eczema in a mouse model and is expected to provide a new, efficient, and low toxic preparation for clinical treatment of dermatitis/eczema through the percutaneous system.

Background: Nystatin (Nys) is a fungicidal drug commonly prescribed for candidiasis disease in several administration routes. However, Nys is a class IV drug, according to the Biopharmaceutical Classification System, that possesses limited bioavailability and is used for local activity. Objective: This study developed and characterized nystatin:β-cyclodextrin (Nys:βCD) inclusion complexes and evaluated their activity against Candida spp. Methods: Complexes were characterized by physicochemical techniques and drug dissolution profiles. The susceptibility of C. albicans, C. krusei, C. parapsilosis, C. glabrata, C. guilliermondii, C. tropicalis, and C. auris was assessed using the broth microdilution method. The applicability of Nys:βCD inclusion complex was evaluated by incorporating it into a temporary soft material for denture stomatitis treatment. Results: Nys was better complexed in a 1:1 molar ratio by freeze-drying and spray-drying methods. The inclusion complexes show bi-exponential release, an initial burst release followed by a sustained manner, presenting higher dissolution efficiency than raw Nys. The 1:1 freeze-drying Nys:βCD complex presents antifungal activity against all evaluated Candida strains, showing the maintenance of the drug effectiveness. The inclusion complex incorporated into a tissue conditioner material for denture stomatitis treatment effectively inhibited more than 90% of C. albicans biofilm growth during 7 and 14 days, in a half dose compared to raw Nys. Conclusion: This work represents a significant contribution to treating a wide variety of diseases caused by the Candida species, optimizing the drug bioavailability and compliance to the treatment due to improved drug solubility, dissolution, and sustained delivery.

Background: Rivaroxaban is widely used for long-term prevention and maintenance therapy of thromboembolic disorders. The existing oral dosage forms of rivaroxaban lead to poor patient adherence because of repeated daily administration. The aim of this study is to design long-acting rivaroxaban- loaded microspheres to reduce dosing frequency and improve patient compliance. Methods: Rivaroxaban-loaded microspheres were prepared using the emulsion-solvent evaporation method. The microspheres were evaluated in terms of morphology, particle size, drug loading and encapsulation efficiency, the physical state of the drug in the matrix, in vitro release/release mechanism, and in vivo pharmacokinetics in Sprague Dawley rats. Results & Discussion: Rivaroxaban-loaded microspheres presented spherical-shaped particles displaying a mean particle size of 89.3 μm, drug loading of 16.5% and encapsulation efficiency of 97.8%. The X-ray diffraction indicated that rivaroxaban existed in crystal form in the microspheres. in vitro release lasting approximately 50 days was characterized as a tri-phasic pattern: (1) an initial burst release, mainly due to the dissolution of drug particles with direct access to the microparticles’ surface, (2) a “plateau” phase with a slow-release rate controlled by the diffusion and (3) a final, rapid drug release phase controlled by polymer erosion. Pharmacokinetic studies showed that rivaroxaban microspheres maintained a sustained release for more than 42 days. Conclusion: Rivaroxaban-loaded microspheres have great potential clinical advantages in reducing dosing frequency and improving patient compliance. The data obtained from this study could be used as scientific evidence for decision-making in future formulation development.

Background: Rhodojaponin III (RJ-III), a characteristic diterpene of Rhododendron molle G. Don, has a wide range of pharmacological activities including anti-inflammatory, antihypertensive, and analgesic effects. However, further research and development have been limited because of its intense acute toxicity and poor pharmacokinetic profile. Objective: In this study, we propose the construction of folic acid–conjugated mesoporous silica nanoparticles (FA-MSNs) as carriers to deliver RJ-III in an attempt to reduce acute toxicity and improve biomedical applications by prolonging drug release and targeting delivery. Methods: FA-MSNs were synthesized and characterized. RJ-III was then loaded into FA-MSNs (RJIII@ FA-MSNs), and the in vitro drug release profile was assessed. Subsequently, the RJ-III@FAMSNs’ cytotoxicity and targeting efficiency were explored in lipopolysaccharide-activated RAW 264.7 cells, and their acute toxicity was investigated in mice. Results: Spherical FA-MSNs were approximately 122 nm in size. Importantly, the RJ-III@FA-MSNs showed prolonged RJ-III release in vitro. Moreover, in lipopolysaccharide-activated RAW 264.7 cells, RJ-III@FA-MSNs not only reduced the cytotoxicity of RJ-III (P < 0.01), but also showed a good targeting effect from the results of cellular uptake. Additionally, the acute toxicity results demonstrated that RJ-III@FA-MSNs improved the LD50 value of RJ-III in mice by intraperitoneal injection 10-fold. Conclusion: This is the first study to use FA-MSNs as carriers of RJ-III to reduce the acute toxicity of RJ-III. The results confirm the potential for targeted delivery of RJ-III in inflammatory cells to enhance efficacy, as well as providing data for future investigations on anti-inflammatory activity.

Background: The skin is one of the most essential organs of the body that plays a vital role. Protecting the skin from damage is a critical challenge. Therefore, the ideal wound dressing that has antibacterial, mechanical, biodegradable, and non-toxic properties can protect the skin against injury and accelerate and heal the wound. Objective: In this study, a nano-wound dressing is designed for the first time. This work is aimed to optimize and act as a dressing to speed up the wound healing process. Methods: Graphene Oxide (GO) was produced by the hummer method. In the next step, GO-copper (Cu) nanohybrid was prepared, then GO-Cu -Curcumin (Cur) nanohybrid was synthesized. Using the electrospinning method, polyvinyl alcohol (PVA)/GO-Cu -Cur were spun, and finally, related analyses were performed to investigate the properties and synthesized chemicals. Results: The results showed that the nanocomposite was synthesized correctly, and the diameter of the nanofibers was 328 nm. The use of PVA improved the mechanical properties. In addition, the wound dressing had biodegradable, antimicrobial, and non-toxic properties. The results of the scratch test and animal model showed that this nanocomposite accelerated wound healing and after 14 days showed 92.25% wound healing. Conclusion: The synthesized nanocomposite has the individual properties and characteristics of an ideal wound dressing and replaces traditional methods for wound healing.